Hi I have set up a wifi ethernet bond with the following commands
      on a Debian stretch machine, nmcli tool, version 1.6.2. 
    
    
      
    
    # nmcli
                  con add type bond ifname wifiether
                  mode
                active-backup
    
      
    #
                    nmcli
                  con add type wifi
                ifname
                wlp3s0
                ssid
                  ganesha master
                  wifiether
    
      
    #
                    nmcli
                  con add type ethernet ifname enp0s25
                  master wifiether
    
      
    
      
    
      
    #
                    nmcli
                      con up bond-slave-wlp3s0
    
      
    #
                    nmcli
                      con up bond-slave-enp0s25
    
      I have
                      the wifi-security section on made the eth0 to be
                      the primary. Witch so far works good.
    I have problems on when I lose the wifi 
                          
    connection and on reboot, the wifi adapter gets disconnected
                                      and stays so, therefore the
                                      slave cannot connect again. 
                                    
    After simply
                                      turning wifi on and off the
                                        slave reconnects again and
                                          every thing is working again.
                                                
                                              
    What
                                                  do i miss?
                                        
                                      
    Tell me
                                            what additional
                                            information do you
                                              need, i did not want to
                                              blow this mail.
    kind
                                                regards,
    kocj